Sole structure for electrostatic dissipative footwear and method of making same

Abstract

A sole and printed circuit assembly for an article of electrostatic dissipative footwear. The present invention also includes a method of manufacturing a sole for an article of electrostatic dissipative footwear.

What is claimed is:  
     
         1 . An electrostatic circuit for a sole having an outsole, an insole and a midsole positioned between the insole and outsole, said electrostatic circuit comprising: 
 a first substrate having a first end and a second end;    at least one conductor path attached to said first substrate, each said conductor path having a first exposed end adjacent said first end of said first substrate and being attachable to the outsole and a second exposed end adjacent said second end of said substrate and attachable to the insole; and    at least one resistor electrically coupled to each said conductor path and mounted to said first substrate.    
     
     
         2 . The electrostatic circuit of  claim 1  wherein said first substrate is flexible and extends through an opening in the midsole.  
     
     
         3 . The electrostatic circuit of  claim 1  further comprising a second substrate attached to said first substrate such that a central portion of each said conductor path is encapsulated between said first and second substrates, said second substrate not covering said first and second ends of each said conductor path.  
     
     
         4 . The electrostatic circuit of  claim 3  further comprising a moisture barrier wrapped around a portion of said first and second substrates and covering said resistors.  
     
     
         5 . The electrostatic circuit of  claim 1  wherein said first and second exposed ends of each said conductor path are adjacent a first side of said first substrate and wherein said electrostatic circuit further comprises a first adhesive attached to a second side of said first substrate adjacent said first and second ends thereof.  
     
     
         6 . The electrostatic circuit of  claim 5  further comprising a second adhesive for affixing said first end of each said conductor path to the outsole and said second end of each said conductor path to the insole.  
     
     
         7 . The electrostatic circuit of  claim 1  wherein the total impedance provided by said resistors is less than or equal to 10 7  ohms.  
     
     
         8 . The electrostatic circuit of  claim 1  wherein said first substrate is flexible.  
     
     
         9 . The electrostatic circuit of  claim 8  wherein said first substrate is fabricated from a polyimide sheet material having a thickness of approximately 25 μm.  
     
     
         10 . An electrostatic circuit for a sole having a conductive outsole, a conductive insole and a nonconductive midsole between the insole and outsole, said electrostatic circuit comprising: 
 a first substrate having a first end and a second end;    a first conductor path attached to said first substrate, said first conductor path having a first exposed end adjacent said first end of said first substrate and being attachable to the conductive outsole and a second exposed end adjacent said second end of said first substrate and attachable to the conductive insole;    a first resistor supported on said first substrate and electrically coupled to said first conductor path;    a second conductor path attached to said first substrate, said second conductor path having a first exposed end adjacent said first end of said first substrate and being attachable to the conductive outsole and a second exposed end adjacent said second end of said first substrate and attachable to the conductive insole;    a second resistor supported on said first substrate and electrically coupled to said second conductor path;    a third conductor path attached to said first substrate, said third conductor path having a first exposed end adjacent said first end of said first substrate and being attachable to the conductive outsole and a second exposed end adjacent said second end of said substrate and attachable to the conductive insole; and    a third resistor supported on said first substrate and electrically coupled to said third conductor path.    
     
     
         11 . The electrostatic circuit of  claim 10  wherein said first substrate is flexible and extends through an opening in the nonconductive midsole.  
     
     
         12 . The electrostatic circuit of  claim 10  further comprising a second substrate attached to said first substrate such that a central portion of each said first, second and third conductor paths is encapsulated between said first and second substrates, said second substrate not covering said first and second ends of each said first, second and third conductor paths.  
     
     
         13 . The electrostatic circuit of  claim 12  further comprising a moisture barrier wrapped around a portion of said first and second substrates and covering said first, second and third resistors.  
     
     
         14 . The electrostatic circuit of  claim 10  wherein said first and second exposed ends of each said first, second and third conductor paths are adjacent a first side of said first substrate and wherein said electrostatic circuit further comprises a first adhesive attached to a second side of said first substrate adjacent said first and second ends thereof.  
     
     
         15 . The electrostatic circuit of  claim 14  further comprising a second adhesive for affixing each said first end of said first second and third conductor paths to the conductive outsole and each said second end of said first, second and third conductor paths to the conductive insole.  
     
     
         16 . A sole for a conductive shoe, said sole comprising: 
 an outsole;    a midsole adjacent said outsole;    an insole adjacent said midsole; and    a printed circuit comprising:    a first substrate;    at least one conductor path attached to said first substrate, each said conductor path having a first end attached to said outsole and a second end attached to said insole; and    at least one resistor electrically coupled to each said conductor path and mounted to said first substrate.    
     
     
         17 . The sole of  claim 16  wherein said first substrate is flexible and extends through an opening through a portion of said midsole.  
     
     
         18 . The sole of  claim 17 , further comprising an undercut area in said midsole adjacent said opening, said undercut area sized to accommodate at least a portion of at least one of said resistors therein.  
     
     
         19 . The sole of  claim 16  further comprising a sock liner adjacent said insole.  
     
     
         20 . The sole of  claim 16  wherein said outsole is fabricated from material selected from the group consisting of polyurethane and rubber.  
     
     
         21 . The sole of  claim 16  wherein said outsole has an electrical resistance value of less than 1×10 6  ohms.  
     
     
         22 . The sole of  claim 16  wherein said midsole is fabricated from material selected from the group of polyurethane and EVA.  
     
     
         23 . The sole of  claim 16  wherein said midsole has an electrical resistance value of greater than 1×10 7  ohms.  
     
     
         24 . The sole of  claim 16  wherein one side of said outsole has a tread pattern thereon.  
     
     
         25 . The sole of  claim 16  wherein said insole is fabricated from polyurethane and carbon powder.  
     
     
         26 . The sole of  claim 16  wherein said insole has an electrical resistance value of less than 1×10 6  ohms.  
     
     
         27 . The sole of  claim 19  wherein said sock liner is fabricated from polyurethane and carbon powder.  
     
     
         28 . The sole of  claim 16  wherein said sock liner has a resistance value of less than 1×10 6  ohms.  
     
     
         29 . The sole of  claim 17  wherein said flexible substrate comprises a polyimide sheet material.  
     
     
         30 . A sole for a conductive shoe, said sole comprising: 
 an outsole having an electrical resistance value of less than 1×10 6  ohms;    a midsole adjacent said outsole and having an electrical resistance value of greater than 1×10 7  ohms;    an insole adjacent said midsole and having an electrical resistance value of less than 1×10 6  ohms; and    a printed circuit comprising:    a first substrate;    at least one conductor path attached to said first substrate, each said conductor path having a first end attached to said outsole and a second end attached to said insole; and    at least one resistor electrically coupled to each said conductor path and mounted to the first substrate.    
     
     
         31 . The sole of  claim 30  further comprising a sock liner adjacent said insole and having an electrical resistance value of less than 1×10 6  ohms.  
     
     
         32 . A sole for an item of footwear, said sole comprising: 
 an outsole having a predetermined electrical impedance;    a midsole adjacent to said outsole and having a predetermined electrical impedance that is greater than said predetermined electrical impedance of said outsole;    an insole adjacent said midsole and having a predetermined electrical impedance that is less than said predetermined electrical impedance of said midsole;    a substrate extending between said outsole and said insole;    a conductor on said substrate and having one end attached to said outsole and another end attached to said insole; and    a resistor attached to said conductor.    
     
     
         33 . The sole of  claim 32  further comprising a sock liner adjacent said insole and having a predetermined electrical impedance that is less than said predetermined electrical impedance of said midsole.  
     
     
         34 . A method for applying a desired amount of electrical impendence to an electrostatic current passing through a shoe having an outsole, an insole and a midsole between the outsole and insole, said method comprising: 
 affixing one end of a first conductive path formed on a substrate to the outsole;    electrically coupling a first resistor having the desired amount of impedance to the conductive path; and    affixing another end of the first conductive path to the insole.    
     
     
         35 . The method of  claim 34 , further comprising: 
 affixing one end of a second conductive path formed on the substrate to the outsole;    electrically coupling a second resistor to the second conductive path, the first and second resistors providing the desired amount of impedance; and    affixing another end of the second conductive path to the insole.    
     
     
         36 . The method of  claim 35 , further comprising: 
 affixing one end of a third conductive path formed on the substrate to the outsole;    electrically coupling a third resistor to the third conductive path, the first, second and third resistors providing the desired amount of impedance; and    affixing another end of the third conductive path to the insole.    
     
     
         37 . The method of  claim 34  wherein said affixing one end of the first conductive path comprises attaching the one end of the first conductive path to the outsole with a conductive adhesive and wherein said affixing another end of the first conductive path to the insole comprises attaching the another end of the first conductive path to the insole with conductive adhesive.  
     
     
         38 . The method of  claim 35  wherein said affixing one end of the second conductive path comprises attaching the one end of the second conductive path to the outsole with a conductive adhesive and wherein said affixing another end of the second conductive path to the insole comprises attaching t he another end of the second conductive path to the insole with conductive adhesive.  
     
     
         39 . The method of  claim 36  wherein said affixing one end of the third conductive path comprises attaching the one end of the third conductive path to the outsole with a conductive adhesive and wherein said affixing another end of the third conductive path to the insole comprises attaching the another end of the third conductive path to the insole with conductive adhesive.  
     
     
         40 . The method of  claim 34  further comprising extending a portion of the substrate through a portion of the midsole.  
     
     
         41 . A method of manufacturing a sole for a conductive shoe, comprising: 
 affixing a first conductive path to a substrate such that the first conductive path has a first exposed end and a second exposed end;    attaching a first resistor to the first conductive path;    forming a conductive outsole;    forming a non-electrically conductive midsole;    supporting the nonelectrically conductive midsole on the electrically conductive outsole;    forming an electrically conductive insole;    attaching the electrically conductive insole to the non-electrically conductive midsole; and    supporting the substrate within the midsole such that the first exposed end of the first conductive path is in electrical contact with the electrically conductive outsole and the second end of the first electrically conductive path is in electrical contact with the electrically conductive insole.    
     
     
         42 . The method of  claim 41  further comprising: 
 affixing the first exposed end of the first electrically conductive path to the electrically conductive outsole; and  
 affixing the second exposed end of the first electrically conductive path to the electrically conductive insole.  
 
     
     
         43 . The method of  claim 41  further comprising: 
 affixing a second conductive path to the substrate such that the second conductive path has a first exposed end and a second exposed end; and  
 attaching a second resistor to the second conductive path, said substrate supported within said midsole such that the first ends of the first and second electrically conductive paths are in contact with the electrically conductive outsole and the second ends of the first and second electrically conductive paths are in contact with the electrically conductive insole.  
 
     
     
         44 . The method of  claim 43  further comprising: 
 affixing the first exposed ends of the first and second electrically conductive paths to the electrically conductive outsole; and  
 affixing the second exposed ends of the first and second electrically conductive paths to the electrically conductive insole.  
 
     
     
         45 . The method of  claim 43  further comprising: 
 affixing a third conductive path to the substrate such that the third conductive path has a first exposed end and a second exposed end; and  
 attaching a third resistor to the third conductive path, the substrate supported within said midsole such that the first ends of the first, second and third electrically conductive paths are in contact with the electrically conductive outsole and the second ends of the first, second and third electrically conductive paths are in contact with the electrically conductive insole.  
 
     
     
         46 . The method of  claim 45  further comprising: 
 affixing the first exposed ends of the first, second and third electrically conductive paths to the electrically conductive outsole; and  
 affixing the second exposed ends of the first, second and third electrically conductive paths to the electrically conductive insole.